The team from Cardiff University have made a training DVD based entirely on verbatim recordings of patients and staff.

Dr Win Tadd, who led the research, said: “Staff were so busy running around that they didn’t often realise the impact of what they said or did on the individual.”

Some behaviour was meant to be friendly but ended up being patronising, such as calling patients ‘sweetie’ or by pet names.

Other incidents were far more serious.

Dr Tadd was present when the woman died in the chair, which was also witnessed by another female patient.

Dr Tadd recorded a subsequent conversation between that patient and her daughter.

The patient said: "She died all alone in that chair. Do you know all she wanted was to lie her old bones on that bed?

"Suppose they were too busy, checking those blasted charts. Honestly, it’s awful. I’ve seen them stood at the end of the bed. They don’t seem to notice what’s going on underneath their noses.”

The man who needed the lavatory was palmed off from nurse to nurse, with one broadcasting to the ward: “Can you take him to the toilet, I’ve got to see to this one?”

Dr Tadd said: "To be treated as an object is appalling; to be ignored when you are asking for help is appalling."

Staff almost always wanted to do a good job, she said, but often did not realise the impact of their behaviour.

Sometimes their workload made good care impossible, but other times it was a question of being poorly trained to deal with elderly people with multiple health problems - often including dementia.

She said: “Sometimes staff ended their shifts in tears, because they couldn’t provide the care they wanted to.”

She and colleagues visited wards at four hospital trusts and health boards in England and Wales.

Dr Tad said she witnessed some “wonderful” care, such as staff who explained procedures clearly, took trouble to ensure patients ate and had water available, and knew how to deal with those with dementia.

But she said the variability of care - not just between wards but often between shifts - was "disturbing".

The DVD, called Dignity - A Tale of Two Wards, is being sent to all NHS trusts and universities that train health staff.

Fiona Phillips, the television presenter, who lost both parents to Alzheimer’s, said the DVD would help staff “reflect on their actions as well as showing what dignified, person-centred care for older people looks like".